JPS6229008B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a balance test method for a lightweight rotating body such as a rotary vane used in a turbocharged internal combustion engine, and a rotating body holding device used in this method.

Conventionally, in a balancing test for a rotating body, the rotating body is inserted into and fixed on the rotating body supporting shaft of a balancing test machine, and in this state, the shaft is rotated at a predetermined speed, and the amount of unbalance at each angular position of the rotating body is measured. This is detected and corrections are made, such as removing or adding mass to the rotating body. Therefore, if the rotating body changes its angular position with respect to the axis during the test, accurate measurements cannot be made. Therefore, usually
The rotating body is screwed to the shaft with a nut or the like to hold the rotating body immovably relative to the shaft.

However, in a balance test of a lightweight rotating body such as a rotary blade for a turbocharger that weighs only about 50 g at most, if the conventional screw fastening with a nut is used, the amount of unbalance of the rotating body itself is small, and the amount of unbalance of the nut or shaft is small. cannot be ignored. Therefore,
There is an unavoidable drawback that balance fluctuation occurs each time the screw is tightened, and as a result, the precision of balancing is significantly impaired. Furthermore, screw fastening requires time to attach and detach, resulting in poor productivity. In addition, when tightening screws, the symmetry may be disrupted due to bending deformation of the rotating body, damage to the shaft or nut, or the provision of a tool engagement surface, which may lead to a deterioration of balance accuracy. It is the cause.

SUMMARY OF THE INVENTION Accordingly, the object of the present invention is to provide a method for performing a balance test of a lightweight rotating body with high accuracy and a rotating body holding device for carrying out this method, solving the above-mentioned conventional drawbacks. be.

The present invention will be explained below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of the configuration of a balance testing machine, in which a rotating body 12 to be tested is mounted on a rotating body supporting shaft 10. The shaft 10 has bearings 13, 13' at both ends thereof.
Supported by Reference numerals 14 and 14' designate pickups for detecting displacements occurring in the bearings 12 and 12' during rotation of the shaft 10, and electrical signals from these pickups are detected by the balance measuring circuit 16.

The inventive mounting of the rotating body 12 on the rotating body carrying shaft 10 is shown in FIG. The shaft 10 is the rotating body 1
2 and the shaft 1 of the rotating body 12
It consists of a collar part 103 as a stopper for regulating the position above 0, and a part 105 with a somewhat smaller diameter other than these parts 101 and 103. Since the shape of the shaft 10 is rotationally symmetrical about the axis at all locations, it can be manufactured by simple lathe processing, and unbalance is unlikely to occur.

The rotating body 12 is assumed to be a rotating blade used in a turbocharger. The rotating body 12 has a center hole 121
, which is fitted onto the portion 101 of the shaft 10. At this time, although the gap S between the rotating body 12 and the portion 101 is exaggerated in the figure, the fit is the same as in the conventional case, and the fit can be inserted without resistance at room temperature.
Incidentally, although this gap S is a cause of unbalance, it is well known that it does not pose much of a problem. In addition, since the collar portion 103 only serves as a stopper for the rotating body 12, the collar portion can be adjusted to a size that does not interfere with the cutting of the rotating body during correction work after detecting an unbalance. The diameter of 103 can be set small.

The holder 20 is shaped like a split sleeve (see FIG. 3), and includes a base 201 and an elastically deformable claw 203 extending from the base.
The claw portion 203 has a dogleg-shaped cross-sectional shape that is slightly bent inward, and when inserted into the small diameter portion of the shaft 10, the claw portion 203 expands in the radial direction and restrains the rotor 12 on the shaft 10. generate the power to Note that the width and depth of the slits 205 formed between the claws 203 are selected so as to obtain an appropriate elastic action.

When using the rotating body holding device of the present invention described above, the rotating body 12 is inserted into the shaft 10 until it contacts the collar portion 103, and then the holder 20 is inserted until it contacts the rotating body 12. As a result,
The end face of the rotating body 12 and the end face of the collar portion 103 as well as the end face of the holder 20 and the end face of the rotating body 12 are brought into frictional contact, and thus the rotating body 12 is mounted and held on the shaft 10. That is, since the rotating body 12 is lightweight at about 50 g, it can be held sufficiently stably even if only by frictional contact.

For the balance test, the shaft 10 is attached to the bearing 1 as shown in Fig. 1.
3 and 13', a predetermined rotation is applied thereto, the unbalance at each angular position of the rotating body 12 is inspected by the measuring circuit 16, and necessary corrections are made. During the rotation of the shaft 10, the angular position of the rotating body does not move due to the elastic frictional contact effect of the holder 20.

Incidentally, in order to remove the holder 20 shown in FIG. 2, a tapered hollow member 22 as shown in FIG. 4 is used. In this way, damage caused by the claws 203 will not occur when the holder 20 is attached and detached, and the attachment and detachment can be carried out quickly. Further, an appropriate surface hardening treatment may be applied to the shaft at the engaging portion with the claw 203.

In the balance test using the holder of the present invention as described above, unlike conventional screw fastening, no deformation is caused to the rotating body, and since the holder 20 is sleeve-shaped and has a completely rotationally symmetrical pair, It is possible to prevent the occurrence of unbalance as in the case of nuts. As a result, a balance test of a lightweight rotating body can be performed with high accuracy. Further, since the rotating body can be held by simply inserting the sleeve, work efficiency is improved compared to the conventional one.

In addition, this holder 20 is only inserted onto the shaft on the opposite side of the stopper 103, and the clearance between the shaft portion 101 and the center hole 121 of the rotating body 12 is substantially free of play, as in the conventional case. It can be set as follows. Therefore, highly accurate balancing work can be maintained.

FIG. 5 shows a further variant in which the retainer is formed as an annular rubber 46. The holder 46 as a rubber ring is fitted onto the shaft 10 with some stretching,
Moreover, by being forced onto the end surface of the rotating body 12, a frictional contact force that holds the rotating body is generated.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the balance test machine, FIG. 2 is a longitudinal cross-sectional view showing the rotating body mounted on the shaft by the holding device of the present invention, and FIG. Front view of the holder shown from the direction shown in the figure, No. 4
FIG. 5 is a view showing a jig for detaching the holder, and FIG. 5 is a longitudinal cross-sectional view showing attachment of a rotating body according to another modification of the holder of the present invention. 10... shaft, 12... rotating body, 13, 13'...
...Bearing, 20, 42, 46... Holder, 103...
...stoppa, 203...claws.

Claims (1)

[Claims] 1 A holding device for a rotating body used during a balance test of a lightweight rotating body, which has a stopper part formed on the rotating body supporting shaft of a balance testing machine to regulate the position of the rotating body on the axis. , a removable holder is arranged on the shaft on the opposite side of the rotating body from the stopper part, and the removable holder applies the frictional force that holds the rotating body in contact with the stopper part between the rotating shaft and the holder. A rotating body holding device that makes the most of its performance.